Variable cryosurgical probe planning system

ABSTRACT

A cryosurgical system for assisting an operator in placing and operating cryosurgical probes in the prostate of a human patient. The cryosurgical system includes a computer system being programmed with software capable of performing the following steps: a) capturing a plurality of transverse views of the prostate; b) capturing a sagittal view of the prostate; c) outlining the capsule of the prostate, the urethra and the rectal wall of the patient with the assistance of the operator, utilizing the captured plurality of transverse views and the captured sagittal view; d) constructing a 3-dimensional model of the prostate, the urethra and the rectal wall utilizing the outlines of step c), above; and, e) utilizing the 3-dimensional model of the prostate, the urethra and the rectal wall to determine i) the number of cryosurgical probes to be utilized; ii) probe settings; and, iii) probe placement positions. The resultant ice thus produced by the cryosurgical probes is optimized for a specific patient.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to computer guided cryosurgery and moreparticularly to a system that utilizes a computer program optimizing thegeneration of resultant ice produced for a specific patient.

2. Description of the Related Art

Cryosurgery involving the use of a cryosurgical probe assembliestypically involves the use of cryoprobes that are each attached to ahandle that are, in turn, connected to a high-pressure fluid lineattached to a fluid source. Cryosurgical ablation of the prostate hasgenerally required relatively small iceballs, i.e. 4 cm diameter by 6 cmlength. For other applications, for example, renal applications,relatively larger iceballs are desired. Many other potentialapplications of cryosurgery may also require larger iceballs such as toablate renal tumors, hepatic tumors, and pulmonary and thoracic tumors.Relatively large iceballs may also be required for palliativeintervention.

The ultimate goal in a cryosurgical procedure is to freeze all tumortissue by lethal ice to kill tumor and not to freeze any benign tissuesurround tumor tissue by lethal ice to avoid complications. Due tovariations of tumor size and shape, it has always been a great challengefor a cryosurgeon to precisely place multiple cryosurgical probes intodesired locations of a tumor and control them so as to generate anoptimum lethal iceball that is tailored to fit the tumor.

SUMMARY OF THE INVENTION

In a broad aspect, the present invention is a cryosurgical system forassisting an operator in placing and operating cryosurgical probes inthe prostate of a human patient. The cryosurgical system includes acomputer system being programmed with software capable of performing thefollowing steps:

a) capturing a plurality of transverse views of the prostate;

b) capturing a sagittal view of the prostate;

c) outlining the capsule of the prostate, the urethra and the rectalwall of the patient with the assistance of the operator, utilizing thecaptured plurality of transverse views and the captured sagittal view;

d) constructing a 3-dimensional model of the prostate, the urethra andthe rectal wall utilizing the outlines of step c), above; and,

e) utilizing the 3-dimensional model of the prostate, the urethra andthe rectal wall to determine i) the number of cryosurgical probes to beutilized; ii) probe settings; and, iii) probe placement positions.

The resultant ice thus produced by the cryosurgical probes is optimizedfor a specific patient.

The cryosurgical system preferably includes an ultrasound system andgraphical depth guide software capable of providing a graphical overlayon an ultrasound image for assisting in the placement of thecryosurgical probes.

Although the present inventive principles will be discussed in detailwith respect to their application to the prostate they may have manyadditional applications. Some additional particular applications includeablation of renal tumors, hepatic tumors, and pulmonary and thoracictumors. Relatively large iceballs may also be required for palliativeintervention. Such additional applications involve the selection ofregions of interest and subregions within these regions in order toprovide the modeling.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is flow chart illustrating, in a broad aspect, the stepsimplemented by the software of the computer system of the cryosurgicalsystem of the present invention.

FIG. 2 is a more detailed flow chart of a preferred embodiment of thesteps of the computer system.

FIG. 3 is flow chart of the probe placement algorithm of FIG. 2.

FIG. 4A is a schematic illustration of a transverse view of the prostatecapsule showing parameters utilized by the computer system of thepresent invention, this transverse view being taken at a middle sectionof the prostate.

FIG. 4B is a schematic illustration of another transverse view of theprostate, this view being taken at the apex of the prostate.

FIG. 4C is a schematic illustration of another transverse view of theprostate, this view being taken at the base of the prostate.

FIG. 5 is a schematic illustration of a sagittal view of the prostatetaken at the center of the prostate.

FIG. 6 is a schematic illustration of a top view of the prostate.

FIG. 7 is a block diagram of a preferred embodiment of the cryosurgicalsystem of the present invention.

FIG. 8 is an example screen display showing a captured image of theoutline of the middle gland of the prostate on the transverse view.

FIG. 9 is an example screen display showing the utilization of the depthguide of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

Referring now to the drawings and the characters of reference markedthereon, FIG. 1 illustrates, in a broad aspect, the steps implemented bythe computer system of the present invention to optimize usage ofcryosurgical probes for a specific patient. These steps are designatedgenerally as 10. In a first step, the computer system captures aplurality of transverse views of the prostate, as noted by numeraldesignation 12. It then captures a sagittal view of the prostate(process block 14). The capsule of the prostate, the urethra and therectal wall of the patient are outlined with the assistance of theoperator, utilizing the captured plurality of transverse views and thecaptured sagittal view (process block 16). A 3-dimensional model of theprostate, the urethra and the rectal wall is constructed utilizing theoutlines noted above (process block 18). The 3-dimensional model is usedto determine i) the number of cryosurgical probes to be utilized; ii)probe settings; and, iii) probe placement positions (process block 20).The computer system used may be, for example, a PC running on theMicrosoft Windows operating system.

Referring now to FIG. 2 a more detailed flow chart is presented,designated generally as 22, illustrating the steps provided by thecomputer system. Preliminary steps include running a pretest to assuresystem integrity (process block 24). A cryosurgical probe is dipped intosterilized liquid and then cryogenic fluid is passed through thecryosurgical probe. If the cryosurgical probe functions properly, nobubble should appear in the liquid and an iceball should form at the tipof the cryosurgical probe. A received ultrasound image is adjusted(process block 26) utilizing an ultrasound software system, as will bediscussed in detail below. An option is then provided as to whethercryosurgical probe placement planning is to be provided using a singleultrasound image or multiple ultrasound images (process block 28).

If single image planning is selected (see decision block 30) thecomputer system confirms that single image planning has been selectedand then captures the middle gland on the transverse view (process block32). It then outlines the prostate, the urethra and the rectum wall onthe transverse, middle gland view (process block 34).

If multiple image planning is selected (see decision block 30) the stepsdiscussed with respect to FIG. 1 are applied. The computer systemcaptures a plurality of transverse views of the prostate, as noted bynumeral designation 12. It then captures a sagittal view of the prostate(process block 14). The capsule of the prostate, the urethra and therectal wall of the patient are outlined with the assistance of theoperator, utilizing the captured plurality of transverse views and thecaptured sagittal view (process block 16). A 3-dimensional model of theprostate, the urethra and the rectal wall is constructed utilizing theoutlines noted above. The 3-dimensional model is used to determine i)the number of cryosurgical probes to be utilized; ii) probe settings;and, iii) probe placement positions. (See process blocks 18, 20.)

Cryosurgical probe placement locations are then verified (process block36). A first criterion of verification is that each cryosurgical probeshould be positioned at least 5 mm away from a periphery of a urethra. Asecond criterion of verification is that a cryosurgical probe should bepositioned a safe margin away from a rectal wall. A third criterion ofverification is that a distance between two cryosurgical probes that arenext to each other should not exceed the sum of the radii of the lethaliceballs of the two cryosurgical probes. A fourth criterion ofverification is that a distance from a cryosurgical probe to a peripheryof a prostate should not exceed a radius of the lethal iceball of thecryosurgical probe. If all of these criteria are not simultaneously met,one or more of the least critical criteria may be compromised as desiredto provide functionality.

Graphical depth guide software is utilized to direct probe placementunder a depth guide (process block 38). This provides a graphicaloverlay on an ultrasound image of a sagittal view for assisting in theplacement of cryosurgical probes. As will be discussed in detail below,the graphical overlay includes a scale and an icon of a cryosurgicalprobe. The icon is divided into two parts. The first part is colored inblue representing a length of the lethal ice of the variablecryosurgical probe. The second part is colored in while representingnon-lethal ice of the variable cryosurgical probe. The distance from thegraphical overlay to the surface of the ultrasound probe changescorresponding to the variable surgical probe selected. The lengths ofthe lethal ice and non-lethal ice change in a manner corresponding to aselected setting of the variable cryosurgical probe. The icon can bedragged and dropped horizontally along the scale. After determining theoptimal location and the length of desired lethal ice by moving thedepth guide, an operator can select a setting on a variable surgicalprobe accordingly then insert it into a patient along the graphicaldepth guide. Cryosurgical treatment is then commenced (process block40).

Referring now to FIG. 3 the determination, by the computer system, ofvariable probe settings is illustrated, designated generally as 18, 20.This involves constructing the 3-dimensional model and utilizing the3-dimensional model to determine i) the number of cryosurgical probes tobe utilized; ii) probe settings; and, iii) probe placement positions.

In a first step, vertical distances from the urethra to top and bottomcapsules of the prostate are calculated for each captured transverseview (process block 42). Referring now to FIGS. 4A, 4B and 4C,transverse views of the prostate are shown along the largest (mid)section, the apex, and the base, respectively. At the apex, the verticaldistance from the top of the capsule to the urethra is denoted as UTR1.At the largest section, the vertical distance from the top of thecapsule to the urethra is denoted as UTR2. Similarly, at the base, thevertical distance from the top of the capsule to the urethra is denotedas UTR3. Although this example shows three sections captured, additionalsections can be similarly captured and vertical distances (UTRn)calculated. Similar calculations of vertical distances from the urethraat the bottom of the prostate capsule are also provided as denoted UTL1,UTL2, UTL3.

The prostate capsule is then scanned on the sagittal view, from left toright, and the vertical distances from the urethra to the top and bottomcapsule of the prostate at each vertical intersection on the sagittalview are calculated. As shown in FIG. 5 the sagittal view verticaldistances are denoted as USR1, USR2, USR3 . . . USRm defining a USRlist, and USL1, USL2, USL3 . . . USLm thus defining a USL list.

As can be seen in FIG. 3, process block 46, the software then finds thepoints that closely match the distances on the sagittal view to thedistances on the transverse view. In other words, it finds a first ofcoordinates that closely match UTR1 from the USR list, UTL1 from the USLlist, UTR2 from the USR list, UTL2 from the USL list, . . . UTRn fromthe USR list, UTLn from the USL list.

Next, as noted in process block 48, the software calculates the centerheights of the prostate from the top to the bottom of the capsule of theprostate for each captured image on the transverse view, the transverseview center heights being denoted as HT1, HT2, HT3, . . . HTn. See alsoFIGS. 4A-4C.

As noted in process block 50, the prostate capsule is then scanned onthe sagittal view and the vertical heights calculated from the top tothe bottom of the capsule of the prostate, the sagittal view verticalheights being denoted as HS1, HS2, HS3, . . . HSm, defining an HS list.See also FIG. 5.

A second set coordinates that closely match HT1 from the HS list, HT2from the HS list, . . . HTn from the HS list is then determined (processblock 52). The software then utilizes the first set of coordinates andthe second set of coordinates to calculate a final, optimized set ofcoordinates (process block 54).

The horizontal component, D2, of the distance between a first point ofthe optimized set of coordinates and a last point of the optimized setof coordinates, on the sagittal view, can then be calculated (processblock 56).

The horizontal components of the distances between each cryosurgicalprobe and the left of the prostate capsule are calculated for eachtransverse view, denoted as WR1, WR2, WR3, . . . WRn (process block 58).Similarly, the horizontal components of the distances between eachcryosurgical probe and the right of the prostate capsule are calculatedfor each transverse view, denoted as WL1, WL2, WL3, . . . WLn. See alsoFIG. 6.

The software then utilizes selected WR1, WR2, WR3, . . . WRn; selectedWL1, WL2, WL3, . . . WLn; and, D2 to calculate the distances, D1, fromthe first point of the optimized set of coordinates and the left of theprostate capsule, on the transverse view (process block 60).

Selected WR1, WR2, WR3, . . . WRn; selected WL1, WL2, WL3, . . . WLn;and, D2 are utilized to calculate the distances, D3, from the last pointof the optimized set of coordinates and the right of the prostatecapsule, on the transverse view (process block 62).

D1, D2 and D3 are then utilized to determine the length of a resultantlethal ice produced by the cryosurgical probes (process block 64).Appropriate settings of the cryosurgical probes based on the length ofthe resultant lethal ice can then be determined (process block 66).

Referring now to FIG. 7, implementation of the computer system into acryosurgical system is illustrated, the cryosurgical system beingdesignated generally as 70. The cryosurgical system 70 includes acryosurgical probe system, designated generally as 72. The cryosurgicalprobe system 72 includes a plurality of cryosurgical probes 74; acontrol system 76 operatively connected to the plurality of cryosurgicalprobes 74; and, a cryogenic fluid source 78 operatively connectable tothe control system 76. It also includes temperature probes 80.

A temperature data acquisition system 82 acquires the temperature ofselected locations in the vicinity of the prostate utilizing thetemperature probes 80, cryosurgical probes 74 and the control system 76.

An imaging system, preferably an ultrasound system 84, and mostpreferably an integrated ultrasound system is utilized for obtainingselected images of selected locations in the vicinity of the prostate.

A computer system, designated generally as 86, is operatively connectedto the cryosurgical probe system 72 and the ultrasound system 84. Thecomputer system 86 implements the steps outlined above with respect toFIGS. 1-6. It includes an integrated data processing system 88, suitablecomputer input/output devices such as a computer monitor, keyboard andmouse (collectively denoted as 90) and a video output 92. The videooutput 92 is provided so that an operator can conveniently view thedisplay at another location away from the computer monitor itself. Avideo input 94 is provided from an external ultrasound system if anintegrated ultrasound system is not utilized. The ultrasound systemsoftware should be capable of adjusting contrast, brightness, gains,focus, depth, and imaging size of the ultrasound image. Furthermore, theultrasound system software should be capable of measuring a plurality ofdimensions on an ultrasound image and of changing ultrasound views bytoggling ultrasound transducers.

The fluid source may be, for example, a cryosurgical system such as thatmanufactured by present assignee, Endocare, Inc., Irvine, Calif. Such acryosurgical system typically utilizes argon gas from an argon gassource to provide Joule-Thomson cooling of the cryosurgical probes.Alternatively, nitrogen can be used. Alternatively, a fluid supplysystem can be utilized that does not require an external fluid supplysource. Heating of the cryosurgical probes is typically provided by ahelium gas source for providing a helium gas flow through the nozzle ofthe cryosurgical probe. This provides a heating effect. Such heating ofthe cryosurgical probes is provided to unstick the probes from thetreated tissue for cryoprobe removal. The cryosurgical probes may be ofthe type manufactured by present assignee, Endocare, Inc., Irvine,Calif.

A preferred cryosurgical probe is a variable cryosurgical probe such asthat disclosed and claimed in co-owned U.S. patent Ser. No. 11/613,054filed Dec. 19, 2006 to Duong, et al. entitled “Cryosurgical Probe WithVacuum Insulation Tube Assembly,” incorporated herein by reference inits entirety. Ser. No. 11/613,054 is assigned to present assignee,Endocare, Inc., Irvine, Calif. and bears the Internal Docket No.ENDO162.

Another variable cryosurgical probe is disclosed and claimed in co-ownedU.S. Pat. Publication US 20050192565 (U.S. patent Ser. No. 11/116,873),to Eum et al. entitled “Detachable Cryosurgical Probe with BreakawayHandle,” incorporated herein by reference in its entirety. Ser. No.11/116,873 is also assigned to present assignee, Endocare, Inc., Irvine,Calif. and bears the Internal Docket No. ENDO144-CP-CP3.

Other cryosurgical probes are described in U.S. Pat. Publication No.20040267248 (U.S. Ser. No. 10/603,883) (Internal Docket No. ENDO144) toDuong, et al., entitled Detachable Cryosurgical Probe, filed on Jun. 25,2003, incorporated herein by reference in its entirety; and, U.S. Pat.Publication US 20050010200 (U.S. patent Ser. No. 10/828,031) (InternalDocket No. ENDO144CP), to Damasco, et al. entitled “DetachableCryosurgical Probe,” incorporated herein by reference in its entirety.

U.S. Pat. No. 6,643,535 issued to Damasco, et al. entitled “System forProviding Computer Guided Ablation of Tissue,” is also incorporatedherein by reference in its entirety.

A heat exchanger or cryostat is utilized to provide heat exchangebetween inlet gas and outlet gas. Although the heat exchanger ispreferably a coiled fin tube heat exchanger various other types of heatexchangers may be utilized such as a tube-in-tube sintered cryostat,threaded cryostat, coiled/sintered cryostat, or stacked coil cryostat.These different types of cryostats are disclosed and claimed in U.S.Pat. Publication No. 20050010200 (U.S. Ser. No. 10/828,031), entitledDetachable Cryosurgical Probe, filed on Apr. 20, 2004, discussed above.

FIG. 8, is a screenshot of a computer display using present Assignee'sCryocare CS™ System, this screenshot being designated generally as 96.In this screen shot, the user has finished an outline 98 of the prostateand an outline 100 of the urethra, and he is performing an outline 102of the rectal wall. The user can drag each dot 103 around so that theoutline can fit the shape of the rectal wall. This corresponds toprocess block 16 of FIG. 1.

Referring now to FIG. 9, another screen shot is illustrated, designatedgenerally as 104 showing use of a depth guide. The computer system isprogrammed with graphical depth guide software, as discussed above,capable of providing a graphical overlay on an ultrasound image 106 forassisting in the placement of the cryosurgical probes. This depth guidedisplay format includes a first, (i.e. horizontal) scale 108 having aplurality of spaced markers. The cryosurgical probe icon 110 representsa cryosurgical probe. The cryosurgical probe icon 110 is positionedadjacent to the first scale 108. The cryosurgical probe icon defines akill zone 112 (typically colored blue) and a non-lethal zone 114 of thecryosurgical probe. The kill zone 112 represents a lethal temperaturerange and the non-lethal zone represents a temperature above the lethaltemperature range. The kill zone 112 and non-lethal zone 114 cooperatewith the spaced markers 108 to provide a visual guide for placing thecryosurgical probes. These zones are dependent on variable settings ofthe probe.

A second (i.e. vertical) scale 116 orthogonal to the first scale 108 hasa second plurality of spaced markers. The position of the cryosurgicalprobe icon 110 on the second scale 116 defines the distance of thecryosurgical probe 110 from an ultrasound probe, by referring to theimage 106.

Thus, in a broad aspect, the present invention is a cryosurgical systemfor assisting an operator in placing and operating cryosurgical probesin the prostate of a human patient, wherein the cryosurgical probes areinserted through the skin of the perineal area of the patient and intothe prostate. The cryosurgical system includes a treatment system,comprising a computer system which is programmed with software capableof optimizing the resultant ice produced by the cryosurgical probes fora specific patient. An ultrasound imaging system is integrated with thetreatment system, wherein the computer software is programmed to adjustan ultrasound image.

Thus, while the preferred embodiments of the devices and methods havebeen described in reference to the environment in which they weredeveloped, they are merely illustrative of the principles of theinvention. For example, although ultrasound imaging has been described,certain applications may require guidance using various other imagingtechniques such as CT guidance or MRI.

Other embodiments and configurations may be devised without departingfrom the spirit of the invention and the scope of the appended claims.

1. A cryosurgical system for assisting an operator in placing andoperating cryosurgical probes in the prostate of a human patient,wherein the cryosurgical probes are inserted through the skin of theperineal area of the patient and into the prostate, said systemcomprising: a computer system being programmed with software configuredto perform the following steps: a. capturing a plurality of transverseviews of the prostate; b. capturing a sagittal view of the prostate; c.outlining the capsule of the prostate, the urethra and the rectal wallof the patient with the assistance of the operator, utilizing saidcaptured plurality of transverse views and said captured sagittal view;d. constructing a 3-dimensional model of the prostate, the urethra andthe rectal wall utilizing the outlines of step c), above; and, e.utilizing said 3-dimensional model of the prostate, the urethra and therectal wall to determine i) the number of cryosurgical probes to beutilized; ii) probe settings; and, iii) probe placement positions,wherein resultant ice produced by the cryosurgical probes is optimizedfor a specific patient.
 2. The cryosurgical system of claim 1, whereinsaid plurality of transverse views comprise three transverse views. 3.The cryosurgical system of claim 1, wherein said computer systemcaptures a plurality of sagittal views of the prostate.
 4. Thecryosurgical system of claim 1, wherein said plurality of transverseviews comprises three transverse views, said three transverse views,comprising: i) a middle gland view; ii) a base view; iii) and an apexview; and, said step of outlining the prostate, the urethra and therectal wall of the patient, comprises outlining on each of said threetransverse views and said sagittal view.
 5. The cryosurgical system ofclaim 1, wherein said computer system is operable to provide userselectable single image planning or multiple image planning.
 6. Thecryosurgical system of claim 1, wherein said computer system is operableto provide user selectable single image planning or multiple imageplanning, wherein if single image planning is selected, said computersystem, performs the following steps: a. confirming that single imageplanning has been selected; b. capturing the middle gland on thetransverse view; c. outlining the prostate on a middle gland view; d.outlining the urethra on the middle gland view; and, e. outlining therectum wall on the middle gland view.
 7. The cryosurgical system ofclaim 1, further comprising an ultrasound system.
 8. The cryosurgicalsystem of claim 1, wherein said computer system is programmed withultrasound system software capable of adjusting contrast, brightness,gains, focus, depth, and imaging size of an ultrasound image.
 9. Thecryosurgical system of claim 1, wherein said computer system isprogrammed with ultrasound system software capable of measuring aplurality of dimensions on an ultrasound image.
 10. The cryosurgicalsystem of claim 1, wherein said computer system is programmed withultrasound system software capable of changing ultrasound views bytoggling ultrasound transducers.
 11. The cryosurgical system of claim 1,wherein said computer system is programmed with graphical depth guidesoftware capable of providing a graphical overlay on an ultrasound imagefor assisting in the placement of said cryosurgical probes.
 12. Thecryosurgical system of claim 1, wherein said computer system isprogrammed to provide preliminary steps prior to step a), above, saidpreliminary steps, comprising: a. running a pretest to assure systemintegrity; b. adjusting a received ultrasound image utilizing anultrasound software system; and, c. providing an option as to whethercryosurgical probe placement planning is to be provided using a singleultrasound image or multiple ultrasound images.
 13. The cryosurgicalsystem of claim 1, further comprising a cryosurgical probe system,comprising: a. a plurality of cryosurgical probes; b. a control systemoperatively connected to said plurality of cryosurgical probes; and, c.a cryogenic fluid source operatively connectable to said control system.14. The cryosurgical system of claim 1, further comprising a temperaturedata acquisition system for acquiring the temperature of selectedlocations in the vicinity of the prostate.
 15. The cryosurgical systemof claim 1, wherein said steps of constructing said 3-dimensional modeland utilizing said 3-dimensional model, comprise the steps of: a.calculating vertical distances from the urethra to top and bottomcapsules of the prostate for each said captured transverse view, thetransverse view vertical distances being denoted as UTR1, UTR2, UTR3 . .. UTRn, and UTL1, UTL2, UTL3 . . . UTLn; b. scanning the prostatecapsule on said sagittal view and calculating the vertical distancesfrom the urethra to the top and bottom capsule of the prostate at eachvertical intersection on the sagittal view, the sagittal view verticaldistances being denoted as USR1, USR2, USR3 . . . USRm defining a USRlist, and USL1, USL2, USL3 . . . USLm defining a USL list; c. finding afirst of coordinates that closely match UTR1 from said USR list, UTL1from said USL list; UTR2 from said USR list, UTL2 from said USL list, .. . UTRn from said USR list, and, UTLn from said USL list; d.calculating the center heights of the prostate from the top to thebottom of the capsule of the prostate for each captured image on thetransverse view, the transverse view center heights being denoted asHT1, HT2, HT3, . . . HTn; e. scanning the prostate capsule on saidsagittal view and calculating the vertical heights from the top to thebottom of the capsule of the prostate, the sagittal view verticalheights being denoted as HS1, HS2, HS3, . . . HSm, defining an HS list;f. finding a second set coordinates that closely match HT1 from said HSlist, HT2 from said HS list, . . . HTn from said HS list; g. utilizingsaid first set of coordinates and said second set of coordinates tocalculate a final, optimized set of coordinates; h. calculating thehorizontal component, D2, of the distance between a first point of saidoptimized set of coordinates and a last point of said optimized set ofcoordinates, on the sagittal view; i. calculating the horizontalcomponents of the distances between each cryosurgical probe and the leftof the prostate capsule, for each transverse view, denoted as WR1, WR2,WR3, . . . WRn; j. calculating the horizontal components of thedistances between each cryosurgical probe and the right of the prostatecapsule, for each transverse view, denoted as WL1, WL2, WL3, . . . WLn;k. utilizing selected WR1, WR2, WR3, . . . WRn; selected WL1, WL2, WL3,. . . WLn; and, D2 to calculate the distances, D1, from the first pointof said optimized set of coordinates and the left of the prostatecapsule, on the transverse view; l. utilizing selected WR1, WR2, WR3, .. . WRn; selected WL1, WL2, WL3, . . . WLn; and, D2 to calculate thedistances, D3, from the last point of said optimized set of coordinatesand the right of the prostate capsule, on the transverse view; m.utilizing said D1, D2 and D3 to determine the length of a resultantlethal ice produced by the cryosurgical probes; and, n. determiningappropriate settings of said cryosurgical probes based on said length ofsaid resultant lethal ice.
 16. A cryosurgical system for assisting anoperator in placing and operating cryosurgical probes in the prostate ofa human patient, wherein the cryosurgical probes are inserted throughthe skin of the perineal area of the patient and into the prostate, saidsystem comprising: a. a cryosurgical probe system, comprising: i. aplurality of cryosurgical probes; ii. a control system operativelyconnected to said plurality of cryosurgical probes; and, iii. acryogenic fluid source operatively connectable to said control system;b. a temperature data acquisition system for acquiring the temperatureof selected locations in the vicinity of the prostate; c. an ultrasoundsystem for imaging selected locations in the vicinity of the prostate;and, d. a computer system operatively connected to said cryosurgicalprobe system, said temperature data acquisition system and saidultrasound system, said computer system being programmed with softwareconfigured to perform the following steps: i. utilizing output images ofsaid ultrasound system for capturing a plurality of transverse views ofthe prostate; ii. utilizing output images of said ultrasound system forcapturing a sagittal view of the prostate; iii. outlining the prostate,the urethra and the rectal wall of the patient with the assistance ofthe operator, utilizing said captured plurality of transverse views andsaid captured sagittal view; iv. constructing a 3-dimensional model ofthe prostate, the urethra and the rectal wall utilizing the outlines ofstep iii), above; and, v. utilizing said 3-dimensional model of theprostate, the urethra and the rectal wall to determine i) the number ofcryosurgical probes to be utilized; ii) probe settings; and, iii) probeplacement positions, wherein resultant ice produced by the cryosurgicalprobes is optimized for a specific patient.
 17. The cryosurgical systemof claim 16, wherein said computer system is programmed with graphicaldepth guide software capable of providing a graphical overlay on anultrasound image for assisting in the placement of said cryosurgicalprobes.
 18. A cryosurgical system for assisting an operator in placingand operating cryosurgical probes in the prostate of a human patient,wherein the cryosurgical probes are inserted through the skin of theperineal area of the patient and into the prostate, said systemcomprising: a. a treatment system, comprising a computer system beingprogrammed with software capable of optimizing the resultant iceproduced by the cryosurgical probes for a specific patient; and, b. anultrasound imaging system integrated with said treatment system, whereinsaid computer software is programmed to adjust an ultrasound imagewherein said computer system is programmed with software configured toperform the following steps: a) capturing a plurality of transverseviews of the prostate; b) capturing a sagittal view of the prostate; c)outlining the prostate, the urethra and the rectal wall of the patientwith the assistance of the operator, utilizing said captured pluralityof transverse views and said captured sagittal view; d) constructing a3-dimensional model of the prostate, the urethra and the rectal wallutilizing the outlines of step c), above; e) utilizing said3-dimensional model of the prostate, the urethra and the rectal wall todetermine i) the number of cryosurgical probes to be utilized; ii) probesettings; and, iii) probe placement positions, so as to provide saidoptimization of the resultant ice produced by the cryosurgical probesfor a specific patient.
 19. The cryosurgical system of claim 18, whereinsaid computer system is programmed with graphical depth guide softwarecapable of providing a graphical overlay on an ultrasound image forassisting in the placement of said cryosurgical probes.
 20. Acryosurgical system for assisting an operator in placing and operatingcryosurgical probes in a selected region of a human patient, saidcryosurgical system comprising: a computer system being programmed withsoftware configured to perform the following steps: a. capturing aplurality of transverse views of the selected region; b. capturing asagittal view of the selected region; c. outlining selected subregionswithin said selected region, utilizing said captured plurality oftransverse views and said captured sagittal view; d. constructing a3-dimensional model of the selected region and subregions utilizing theoutlines of step c), above; and, e. utilizing said 3-dimensional modelof the selected region and subregions to determine i) the number ofcryosurgical probes to be utilized; ii) probe settings; and, iii) probeplacement positions, wherein resultant ice produced by the cryosurgicalprobes is optimized for a specific patient.